1. Field of the Invention
The present invention relates to expansible interfaces of electronic devices, and particularly to an expansible interface for modularized printed circuit boards (PCBs).
2. Prior Art
Nowadays, modularized PCBs that comprise a primary PCB and a subsidiary PCB are broadly employed in many electronic devices. The primary PCB of the modularized PCBs is assembled with a plurality of main components such as a central processing unit (CPU) and a memory. The subsidiary PCB of the modularized PCBs is an expansible board ancillary to the primary PCB, and is coupled to the primary PCB to form a unified PCB assembly. The modularized PCBs are generally used in routers, uninterruptible power supplies (UPSs), and so on.
Taiwan Patent Publication No. 458,306, issued on Oct. 01, 2001, discloses an expansible interface for modularized PCBs. Referring to FIG. 4, a primary PCB 5 is provided with a CPU 51 and a connector 50. A subsidiary PCB 4 is configured with a connector 40 and a plurality of expansion slots 41. In this invention, the connector 50 on the primary PCB 5 is coupled to the connector 40 on the subsidiary PCB 4 to form a unified PCB assembly for connecting more peripheral devices via the expansion slots 41. The connector 50 on the primary PCB 5 is also electrically connected to a bus on the primary PCB 5, for transmitting data in the bus to the subsidiary PCB 4. The data transmitted by the connector 50 may be Industry Standard Architecture (ISA) data, Peripheral Component Interconnect (PCI) data, or both. However, the electronic device employing the above-mentioned modularized PCBs is not adapted to the market requirements. Because the electronic devices are developed toward light, thin, short and small, the above-mentioned modularized PCBs are inevitably large.
China Patent No. 02248010.2, issued on Aug. 20, 2003, discloses a board-to-board connector assembly. This invention provides an assembly of the modularized PCBs in which the primary PCB and the subsidiary PCB are set in parallel. Although the space occupied by the PCBs is reduced, the communication between the primary PCB and the subsidiary PCB is still inconvenient to use.
In view of the above-mentioned shortcomings, there is a need for an expansible interface for modularized PCBs, for transmitting different kinds of data from the primary PCB to the subsidiary PCB.